Show how orbitals are filled. Orbitals represented by squares and electrons by arrows pointing up and down

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What is Hund's rule?

Single electrons must occupy all empty orbitals within a sub-level before they start to form pairs in orbitals. Repulsion when there are 2e-, most stable configuration is with single electrons in different orbitals.

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What is the Aufbau principle?

How electrons fill up the different shells so lowest energy sub levels are occupied first

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Order of filling up shells?

1s2, 2s2, 2p6, 3s2, 3p6, 4s2, 3d10,4p6, 5s2, 4d10

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What does 4s fill up before 3d?

If 3d is half full or completely full that is the lower energy arrangement eg Fe3+ more stable than Fe2+ as har

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Whats removed first 4s or 3d?

4s-Filling up of orbitals is dependent on orbital energy while removal of electrons from orbitals is dependent on orbital location.

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Electron configuration rules?

1) Fill successive subshells using Aufbau principle eg 1s,2s. 2) Cr and Cu donate one of their 4s electrons to 3d to make a full of half full 3d subshell.

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Electron configuration rules? .2

3) When transition metals become ions they lose their 4s electrons before 3d 4) Electrons fill all orbitals before pairing up

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What is the first ionisation energy of an element?

Energy required to remove one electron from each atom in a mole of gaseous atoms to form one mole of gaseous positive ions

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Eqn for first ionisation energy of sodium?

Na(g)-> Na+(g)+e-

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What is the general trend in ionisation energies across the period for nuclear charge?

Nuclear charge increases as the number of protons increases so there is a greater electrostatic force from the nuclear increasing the ionisation energy

Generally increase however there is a decrease between magnesium and aluminium and phosphorus and sulphur

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Why is there a dip at Magnesium and Aluminium?

Mg's outer electron is in the 3s subshell whereas Al is in the 3d subshell, as it is further away there is a decreased force from the nucleus so means that less energy is needed to remove it

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Why is there a dip at Phosphorus and Sulphur?

Sulfur has the first paired electrons, as they are negatively charged they repel each other reducing the ionisation energy

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Overall successive ionisation energies of sodium?

Overall increase as electron are getting closer to the nucleus so the force us stronger to overcome. Also you are maintaining proton number but less electrons so stronger force

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Why are there jumps?

Electrons are in different shells so each time there will be less shielding but a stronger force as it gets closer to the nucleus eg. 1s1-2s1 3s1 2p6

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First ionisation energies of group 2?

Down the group the i.e decreases. Atomic radius increases so outer electron is further from the nucleus so less energy is needed to remove it (decreased force) Shielding increases as P no inc down grp so less energy is needed to remove the electron

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Mass spec steps?

1. Ionise to give a charge and attract a detector by knocking off an electron by an electron gun (P dislve vacuum ion chamber) 2. Accelerate with an electric field to get the same kinetic energy making only mass affect speed of ions

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3. 4.

Lighter ions dont take as long to reach the detector they move at diff speeds depending to their mass. 4)Detector detect time and changes it into a current, detector has a negative charge to attract the ions.

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5. 6

More ions hitting detector= greater current - relative abundance/no. particles of each mass that hits detector. 6) Mass to charge ratio is calculated from the time of flight

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What does the high energy beam of electrons do? Velocity of particle? What are the positively charged ions electrostatically attracted to?